Blunted Circadian Variation of Blood Pressure in NF1 Patients

Abstract Background: Cardiovascular events such as myocardial infarction and stroke are life-threatening complications associated with Neurofibromatosis type 1 (NF1). As previous studies observed an association between cardiovascular events and the loss of circadian variations of blood pressure, we investigated the 24h circadian rhythm of blood pressure in 24 NF1 patients (10 males and 14 females, with a mean age of 39.5 years ± 14 years) by using ambulatory blood pressure monitoring (ABPM). Results: Only one-third of the patient were dippers, 50% were non-dippers, and 17% were risers. Reduced variability of systolic and diastolic nocturnal blood pressure was observed in NF1 patients compared with several studies of normotensive individuals (p=0.022). In NF1 patients, the blunted systolic nocturnal decline was significantly associated with cumulative tumor burden (presence of a plexiform neurofibroma and a high number of cutaneous neurofibromas) (p=0.002). This association was stronger for plexiform neurofibromas than for cutaneous neurofibromas (p=0.015 versus p=0.078). Conclusions: Most NF1 patients in this study showed a blunted sleep-time BP pattern considered an independent risk factor for cardiovascular events in normotensive and hypertensive individuals. Periodic monitoring of BP should be included in NF1 follow-up guidelines to diagnose unmask hypertension or a non-dipper/riser pattern to implement therapeutic strategies.